Observation device comprising a control unit

ABSTRACT

An observation device is provided with an image acquisition unit comprising at least one image sensor, an image display unit, that is arranged for displaying image data that is provided by the image acquisition unit, an image processing unit for image processing procedures, and a control unit comprising a multi-axis input module. The image acquisition unit is configured to provide recorded images having a predefined recording pixel quantity. The image display unit is configured to display images having a predefined display pixel quantity, wherein the recording pixel quantity is equal to or greater than the display pixel quantity. Image pixels of the display pixel quantity are obtained from the recording pixel quantity. Subsets of the recording pixel quantity are selected to form the display pixel quantity. Image acquisition parameters and display parameters are controlled by the input module. The input module is arranged to be coupled with the image acquisition unit for controlling at least one image acquisition parameter.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority from German patent application 10 2015121 017.7, filed on Dec. 3, 2015. The entire content of that priorityapplication is fully incorporated by reference herewith.

BACKGROUND

The present disclosure relates to an observation device, particularly toa medical observation device, comprising an image acquisition unit, animage display unit, an image processing unit, and a control unit. Thedisclosure further relates to a use of a multi-axis input module.

Observation devices in the context of the present disclosure may involveendoscopes, exoscopes and similar optical instruments. This preferablyinvolves optical instruments that are equipped with image sensors togenerate a digital image of an object to be observed. Instruments ofthat kind are regularly arranged as so-called eyepieceless instruments.In other words, instruments of that kind do not exclusively involve aconventional optical beam path between the objective and an eye of auser.

Instead, eyepieceless instruments regularly involve image display unitsthat are formed as screens, video glasses (head-mounted displays) andsuch like. This may involve several advantages. For instance, aplurality of image display units that can use the same image signal maybe easily coupled.

Further, eyepieceless instruments are known that are configured forstereoscopic visualization. Instruments of that kind for instancecomprise two image sensors that are disposed adjacent to one another andthat comprise a defined offset (distance or offset angle) therebetween.

Image sensors may generally be coupled with appropriate input beamgeometrical optics. In this way, desired optical imaging may beachieved.

The present disclosure, at least in some exemplary embodiments, relatesto observation devices having compact-shape image acquisition units.Both for endoscopes and for exoscopes, small dimensions are appreciated,for instance at the distal end of the instruments. In endoscopes, thismay relate to a cross section or a diameter of the distal end.Endoscopes are regularly arranged to be inserted in body orifices. Tokeep the stress for patients as low as possible, small dimensions areintended. The distal end of an endoscope generally is referred to as theend that is remote from the user and/or the observer. A proximal endthat is opposite to the distal end generally is referred as an end thatis close to the user and/or observer

An exoscope may generally be referred to as microscope. Exoscopes areregularly arranged to observe a target object from exterior of the bodyfrom a defined working distance that may for instance be between 25 to75 cm (centimeter). However, also for exoscopes it is intended to formimage acquisition units, objectives and/or, more generally seen, thedistal end (remote from the observer) in a compact fashion. In this way,a preferably not-obstructed viewing field is provided to the operatingsurgeon. Even when an exoscope is arranged at a defined working distancefrom an object (for instance an operation site to be observed), theaccessibility of the operation site should preferably be extensivelyensured.

The desired compactness involves that in eyepieceless endoscopes andexoscopes frequently complex units for adapting the focal length(optical zoom) are dispensed with. However, applications may beforeseen, wherein only a section of a currently detected object field ata given focal length is interesting. Both for endoscopes and also forexoscopes, the working distance often may not be arbitrarily varied.Because of their compactness, optical instruments that are arranged asendoscopes or exoscopes, for instance, are typically manually guided.However, several applications can be foreseen, wherein the instrument isfixedly attached to a stand or a similar mounting device. For instance,this is an option when an image is desired that is preferablyblurr-free. Further, the fixation of the instrument may have the effectthat for the operating surgeon or an assistant both hands are availablefor other activities.

In eyepieceless instruments, particularly in eyepieceless exoscopes orendoscopes, it is possible to arrange image sensors very close to anobjective of the instruments. As no (optical) eyepiece is provided, itis not required to guide an optical beam path through the instrumentand/or through a considerable portion of the instrument. In other words,close to the distal end of the instrument, an image of the object to beobserved may be detected and converted into electric signals. Based onthe electric signals, image data may be derived. This regularly involvesthat also at the instrument itself certain data-processing capacity isprovided. This may involve at least a limited computing capacity.Further, buffer memories and similar components may be provided.

Further, an eyepieceless instrument generally comprises an interfacethrough which image data may be sent to an image display unit or an(external) image processing unit. Image data may involve so-called rawdata. However, image data already may be processed in the instrumentitself.

No conventional eyepiece is provided by means of which an observationbeam path is directly visible to a human eye (for instance of anoperating surgeon). In an eyepieceless instrument in the context of thepresent disclosure, a conversion and/or transformation of opticalsignals of the observation field into image data is performed and, inturn, the image data is transferred into optical signals, for instancefor the purpose of presentation at a screen.

An exoscope within the general meaning applied in the present disclosureis for instance known from US 2015/0085084 A1. The exoscope disclosedtherein is configured as a stereo-exoscope and comprises stereo opticsfor sensing stereo images.

An observation device arranged as a microscope unit comprising anoperation microscope is known from US 2013/0016204 A1. The microscopedevice further comprises a screen on which invocable device functionsare displayable. For selecting and for activating the displayed devicefunctions, a so-called rotary-push control element is provided. Therotary-push control element comprises two actuation axes, namely arotation axis for rotation actuation, and a translational axis for apush actuation.

In view of this, it is an object of the present disclosure to present anobservation device that is arranged to be operable in a simple and lowerror fashion and that enables a compact-shaped design of at least animage acquisition unit of the observation device.

It is a further object of the present disclosure to present a respectivemedical observation device.

It is a further object of the present disclosure to present anobservation device nevertheless provides extended functions, forinstance the option to select and modify a magnification of the image ofthe object field.

It is a further object of the present disclosure to present anobservation device having a control unit that is operatively coupledwith the observation device in such a way that an intuitive control ofat least part-functions relating to the detection and part-functionsrelating to image displaying is enabled.

It is a further object of the present disclosure to present anobservation device comprising a control unit having a control logicwherein an operator, without doing it intentionally, may easily controlrecorded images that are provided by the image acquisition unit anddisplay images that are provided by the image display unit.

It is a further object of the present disclosure to present anobservation device comprising a control unit wherein, at first, forinstance, it is of no significance from the operators point of viewwhether he/she directly controls an optics of the image acquisitionunit, or controls signal processing and/or data processing relating tothe recorded images by an actuation of the control unit.

It is a further object of the present disclosure to present anobservation device comprising a control unit that enables aninterconnection of the image acquisition unit with the image processingunit and the image display unit, at least in terms of control, whereinthe interconnection operationally couples part-systems with one anotherand, so to say, enables a consistent/integral control of the coupledsystem.

It is a further object of the present disclosure to present beneficialuses of an input module in a control unit for an observation device.This may involve that the input module, in the operators view, enablesan interconnection of part-systems of the observation device, so thatthe operator, using merely one input module, may control the imageacquisition unit, the image display unit and the image processing unitin unison.

SUMMARY

In regard of the observation device, these and other objects areachieved by an observation device comprising:

an image acquisition unit comprising at least one image sensor,preferably a stereo-image acquisition unit comprising two image sensors,

an image display unit that is arranged to display image data that isprovided by the image acquisition unit,

an image processing unit for image processing procedures, and

a control unit comprising a multi-axis input module,

wherein the control unit is configured to provide recorded images havinga predefined recording pixel quantity,

wherein the image display unit is configured to display images having apredefined display pixel quantity, wherein the recording pixel quantityis equal to or greater than the display pixel quantity,

wherein image pixels of the display pixel quantity are obtainable fromthe recording pixel quantity,

wherein, for providing views having different magnifications, subsets ofthe recording pixel quantity are selectable to form the display pixelquantity,

wherein image acquisition parameters and display parameters arecontrollable by the input module, and

wherein the input module is arranged to be coupled with the imageacquisition unit for controlling at least one image acquisitionparameter.

The above aspect is based on the insight that, at least in someexemplary embodiments of the present disclosure, the multi-axis inputmodule of the control unit enables a simple, integrated control of theobservation device. At first, it is of no significance whether anoperator (for instance an operating surgeon or an assistant) controls bymeans of an actual input the image acquisition unit, the imageprocessing unit or the image display unit. As the input module isarranged as a multi-axis input module, the image acquisition unit, theimage display unit and/or the image processing unit may besimultaneously or nearly simultaneously controlled. The result of suchan input is immediately visible to the operator due to a change of thedisplayed image. It is of no significance whether the change of thedisplayed image is induced by influencing the image acquisition unit,the image processing unit or the image display unit. The interconnectionbetween the input module and the image acquisition unit may take placein mediate or immediate fashion. The interconnection between the inputmodule and the image acquisition unit is functional or structural.

The display parameter may be for instance a currently selectedmagnification (zoom factor). The display parameter may further relate toa current position of a displayed image in a provided global recordedimage. To control display parameters of that kind, the input module maymediately or immediately control the image processing unit and/or imagedisplay unit. The image acquisition parameter may for instance relate toa current position and/or a current distance of a focus plane orgenerally a focus parameter. For instance, the image acquisition unit isprovided with a focus drive. Accordingly, the input module may bemediately or immediately coupled with the image acquisition unit tocontrol the focus drive. The image acquisition parameter may, however,further relate to an illumination of the currently observed objectfield. The image acquisition parameter may further relate to anactivation of filters, apertures, mirrors and such like.

In certain embodiments, the observation device is a medical observationdevice. In certain embodiments, the at least one sensor is arranged todetect incident electromagnetic radiation in at least one of an UVrange, a visible light range, and a (N)IR range. As used herein, imagecapturing involves detecting electromagnetic radiation that hassubstantially been reflected by an object to be observed, e.g. by a bodypart or an organ of a patient.

The at least one sensor may be arranged to detect light in at least onesection of a wavelength range between about 10 nm (nanometers) to about1.400 nm. As used herein, ultraviolet light (UV) is an electromagneticradiation with a wavelength from about 10 nm to about 400 nm. As usedherein, visible light is an electromagnetic radiation with a wavelengthfrom about 400 nm to about 700 nm. Near-infrared light (NIR) is anelectromagnetic radiation with a wavelength from about 700 nm to about1.400 nm.

In certain embodiments, the acquisition unit is a stereo-imageacquisition unit comprises two image sensors for stereoscopic imaging.

In an exemplary embodiment, the input module is further arranged to becoupled with the image acquisition unit to control at least one displayparameter. Hence, in accordance with this embodiment, image processingalready takes place, at least partially, at the optical instrumentitself and/or at the image acquisition unit thereof. The displayparameter for instance relates to an image scale (magnification factorand/or zoom factor). If a desired image scale or image section may begenerated by a targeted selection of defined sets or subsets of therecording pixel quantity, also the image acquisition unit itself may beused for image processing to meet with desired display parameters.Similarly, also an image position may be changed when a section of therecording pixel quantity is shifted and/or re-positioned within the areathat is provided by the recording pixel quantity.

In other words, in accordance with this embodiment, the opticalinstrument itself and/or the image acquisition unit thereof are, atleast to some extent, configured for image processing. This may involveproviding views having different magnifications and a digital “shifting”of an image section. This measure has the effect that the data amountthat is exchanged between the image acquisition unit and an externalimage processing unit and/or image display unit is reduced. This mayaccelerate image processing procedures and the provision and/orpresentation of the desired image data.

Hence, a (part-) image processing unit of the image acquisition unit maybe associated with the image acquisition unit and/or the opticalinstrument. In accordance with this embodiment, image processing may beregarded as a distributed task, namely partially in an internal (part-)image processing unit and an external (part-) image processing unit—ineach case in the view of the instrument. The internal (part-) imageprocessing unit may be a part module of the image acquisition unit. Itmay also be envisaged to provide a separate internal (part-) imageprocessing unit at the instrument in addition to the image acquisitionunit.

The image acquisition unit of the observation device is, in certainembodiments, arranged as eyepieceless image acquisition unit. In otherwords, no exclusively optical observation beam path is provided to theoperator. Instead, for instance recording optics is provided, whereinthe at least one image sensor is coupled to the “ocular” of therecording optics. In certain embodiments, the image acquisition unitdoes not comprise an optical zoom. In this way, the image acquisitionunit may be arranged in a considerably compact-design fashion. Forinstance, the image acquisition unit may be arranged as a part of anoptical instrument, for instance an exoscope or endoscope. In certainembodiments, the image acquisition unit is arranged at the distal end ofthe optical instrument. Further, the image acquisition unit is forinstance provided with or coupled to an illumination module.

In certain embodiments, the display unit is configured for immediatelydisplaying (instant or quasi-instant displaying) recorded images. Incertain embodiments, the image acquisition unit is arranged asstereo-image acquisition unit. Accordingly, also the image display unitis then equipped for visualizing stereoscopic images. To this end, theimage display unit may be configured for visualizing two(stereo-)channels. An observer or operator may spatially perceive theimage provided by the image display unit, using suitable means(3D-glasses and such like). Further variations may be envisaged, forinstance providing autostereoscopic screens. It is understood that inaddition to the stereoscopic visualization also a (volumetric)3D-visualization may generally be envisaged.

However, the present disclosure does not relate to a reproduction ofmodels, but to an immediate reproduction (live-reproduction) of anobserved object field. As used herein, immediate reproduction involvesthat an observed scene can be displayed without a temporal delay (lag)that is noticeable by the user (operating surgeon, etc.).

The image processing unit may generally be arranged as central unit.However, in accordance with at least some exemplary embodiments, theimage processing unit is arranged as a distributed image processingunit. In other words, the image processing unit may involve modules atleast one of which is coupled with and/or provided in the imageacquisition unit. In other words, the optical instrument that isprovided with the image acquisition unit may be arranged for processingcaptured (raw) image data. It may therefore be envisaged that the atleast one image sensor provides a continuous or quasi-continuousrecorded image data stream, wherein already in the optical instrument aselection and/or derivation of a display image data stream or at leastof a stream of preprocessed image data takes place. This has the effectthat no complex (separate) computing equipment has to be providedbetween the image acquisition unit and the image display unit.Nevertheless, it may be of course also envisaged that respective imageprocessing modules are provided that are not directly associated withthe image acquisition unit. Image processing modules of that kind may beassociated with the image display unit. However, it may also beenvisaged to provide separate image processing modules that areassociated with a computer.

In certain embodiments, the multi-axis input module is arranged to themediately or immediately coupled with both the image acquisition unitand with the image display unit and/or the image processing unit tocontrol several components of the observation device. To this end, it isnot necessary to provide separate control modules for the imageacquisition unit, the image display unit and, as the case may be, evenfor the image processing unit to control the desired functions.

The afore-mentioned components may be coupled to one another viadiscrete lines. It may however be also envisaged that a common bus lineis used. Further types of communication and/or a network topologybetween the components may be envisaged. It goes without saying that atleast some of the components may also communicate with one another in awireless fashion.

In certain embodiments, the display pixel quantity corresponds to anative resolution of a display of the image display unit. When the imageacquisition unit is provided with an image sensor that comprises a greatnumber of single sensors so that overall a recording pixel quantity ispresent that is greater than the display pixel quantity, a magnificationmay easily be provided when, in the event of an enlarged view of apartial section of a recorded image, each neighboring pixel of thesection is read out. A (reduced-scale) overview may however be used whennot each neighboring pixel but for instance each second or each fourthneighboring pixel is used to derive the display image from the recordedimage. It goes without saying that intermediate stages may be envisaged.For instance, an image sensor may be used that provides a 4K resolution(4096×2160 pixels) or a similar resolution, wherein the visualizationinvolves a HD resolution (for instance Full HD 1920×1080 pixels or HDready 1280×720 pixels).

According to an exemplary embodiment of the observation device, theinput module is coupled with the image acquisition unit and the imageprocessing unit, to operate the image acquisition unit for modifyingimage acquisition parameters, and to operate the image processing unitfor modifying display parameters. In certain embodiments, the inputmodule is operable in at least a first operation mode and a secondoperation mode, wherein in the first operation mode a direct control ofimage acquisition parameters and display parameters is enabled, andwherein in the second operation mode a control of peripheral functionsis enabled. The interconnection may be provided in a mediate orimmediate fashion. A further unit may be arranged between the imageacquisition unit and the image processing unit.

In this way, further peripheral functions can be controlled by means ofthe input module. This may for instance involve a menu control and suchlike. For instance, the input module may be used to influence a rotationorientation (image orientation). Accordingly, the input module mayoperate an actuator that is associated with the image acquisition unitand that is arranged to rotate the at least one image sensor about anaxis that is perpendicular to the image sensor surface.

According to an exemplary embodiment of the observation device, there isfurther provided a positioning drive for the image acquisition unit,wherein the input module, in the second operation mode, is operable tocontrol the positioning drive for positioning the image acquisitionunit. To this end, the image acquisition unit may be mounted to a stand,column, or a rack-like structure involving at least one poweredpositioning axis. As the input module is, in some exemplary embodiments,a multi-axis input module, one and the same element may be actuated tocontrol two, three, or even more powered axes of the positioning drive.

According to a further exemplary embodiment of the observation device,the input module is arranged as single-hand input module, wherein theinput module comprises an actuation element that is manipulable by anoperator, wherein the actuation element provides a plurality of degreesof freedom of movement for inputs, for instance at least onetranslational direction, at least one rotation direction and at leasttwo further degrees of freedom and/or movement directions that arearranged as sliding directions or swivel directions. The single-handinput module may be operated using only one hand. Hence, it is ensuredthat at least a second hand of the operator is available.

In certain embodiments, the input module does not only comprise twodegrees of freedom in the form of a rotation direction for rotation anda translational direction for a push movement. In certain embodiments,at least two further degrees of freedom are available that are forinstance oriented perpendicular to one another and perpendicular to thetranslational direction.

According to a further exemplary embodiment of the observation device,the actuation element is puck-shaped or knob-shaped, wherein theactuation element is coupled with sensors to detect a pull/push movementalong a longitudinal axis of the actuation element, a rotation about thelongitudinal axis, and sliding movements in a plane that is orientedperpendicular to the longitudinal direction, or swivel movements aboutpivot axes that are oriented perpendicular to the longitudinal axis. Incertain embodiments, the actuation element provides a hand rest and/orpalm rest. Hence, the operator may simply put down his/her hand on theactuation element and may at least sectionally encompass the same withhis/her fingers. It goes without saying that embodiments of theactuation element may be envisaged, wherein the operator engages theactuation element only with his/her fingers without resting the palmthereon.

According to a further exemplary embodiment of the observation device,the actuation element is coupled with at least one sensor that isconfigured as displacement transducer or force transducer. In certainembodiments, the actuation element is coupled with a plurality ofsensors for a multi-axial detection of deformations or movements.

Several types of sensors may be envisaged. This may for instance involveoptical sensors that may detect movements of the actuation element. Inthis context, for illustrative purposes, reference is made to opticalsensors of computer mouses.

It may be however also envisaged to design the actuation element as suchnot in a movable fashion. Instead, sensors may be provided that maydetect (minimum) deformations of the actuation element. In other words,the operator may manipulate the actuation element, for instance bycompressing, pulling, twisting and/or bending, wherein the deformationsresulting therefrom may be detected by appropriate sensors. To this end,strain gages or similar sensors may be provided, for instance.

In certain embodiments, two, three or more sensors are used to provide arespective number of degrees of freedom of movement and/or to detect anddiscriminate a corresponding number of defined actuations. It goeswithout saying that the sensors may be arranged to simultaneously detecta plurality of movements (combined actuation movements). This may forinstance involve a simultaneous pulling or pushing in combination with arotation of the actuation element. In this way, using only a singleactuation element, further functions may be controlled.

In addition to the actuation element, the input module may comprisefurther input element, for instance buttons, switches, scroll wheels andsuch like. In certain embodiments, the actuation element itself is notprovided with further input elements. Those may rather be arranged inthe surroundings of the actuation element. Hence, the actuation elementmay be actuated “blind” without the necessity of a visual contact.However, in some exemplary embodiments, it may be envisaged thatactuation buttons or actuation switches directly at the actuationelement for confirming operator inputs are present.

According to a further exemplary embodiment of the observation device,the actuation element is arranged as four-axis actuation element,wherein an actuation of the first actuation axis defines a magnificationand a size of an area of the display image in the recorded image that isassociated with the magnification, wherein an actuation of the secondactuation axis defines a focus setting, wherein an actuation of thethird actuation axis causes a movement of the area that is covered bythe display image in an area that is covered by the recorded image in afirst movement direction, and wherein an actuation of the fourthactuation axis causes a movement of the area that is covered by thedisplay images in the area that is covered by the recorded images in asecond movement direction that is inclined with respect to the firstmovement direction. Accordingly, the actuation element comprises four(movement) degrees of freedom to which the actuation axes are assigned.

In certain embodiments, the first movement direction and the secondmovement direction are oriented perpendicular to one another.

The focus setting may for instance induce a modification or adjustmentof a focus plane. Generally, to this end, optical components of theimage acquisition unit are moved. The image acquisition unit may thencomprise a focus drive. Further, the focus setting may relate to avariation of a depth of field. The actuation of the first actuationaxis, for instance by pushing or pulling, involves a (digital)magnification and/or reduction of the image section that is displayed bythe image display unit. An actuation of the third and/or the fourthactuation axis involves a movement of the image section that iscurrently displayed in a provided image plane. It goes without sayingthat such a movement is not possible when the area that is currentlydisplayed by the image display unit equals the area that is provided bythe image acquisition unit.

The area that is covered by the display images may also be referred toas display area. The area that is provided by the recorded images mayalso be referred to as recording area.

According to an exemplary refinement the first actuation axis provides atranslational direction, wherein the second actuation axis provides arotation direction having an axis that is parallel to the translationaldirection, and wherein the third actuation axis and the fourth actuationaxis respectively provide a sliding direction, for detecting a lateraldeflection perpendicular to the translational direction, or a swiveldirection, for detecting a lateral inclination about axes that areoriented perpendicular to the translational axis. It goes without sayingthat also a combination of a swivel direction and a sliding directionmay be envisaged.

In this way, a plurality of functions may be controlled by merely oneactuation element that is operable by a single hand.

According to a further exemplary embodiment of the observation device,the recording pixel quantity is an integer multiple of the display pixelquantity, wherein the recording pixel quantity is preferably four times,further preferred eight times the display pixel quantity. By way ofexample, the display pixel quantity is 1280×720 (HD), preferably1920×1080 (Full HD). Accordingly, the recording pixel quantity mayamount to two times, four times or even eight times of those values. Incertain embodiments, an aspect ratio (for instance 16:9 or 4:3) ismaintained.

According to a further exemplary embodiment of the observation device,the image processing unit is configured to supply the image display unitwith a display pixel quantity that is arranged to be displayedinterpolation-free. In certain embodiments, this involves a definitionof the display pixel quantity, wherein each display pixel corresponds toa pixel of the recording pixel quantity or to a defined average of a setof pixels (for instance 2×2 or 4×4) of the recording pixel quantity. Inother words, in at least some magnification degrees, the observationdevice enables a loss-free or quasi-loss-free digital zoom. It goeswithout saying that also intermediate stages may be envisaged, whereinan interpolation is required. It also goes without saying that in theevent of a great magnification the to-be-magnified section of therecording area may comprise fewer pixels than the display area, so thatthen an “upscaling” to the format of the display area is performed.Hence, at least some magnification degrees may involve a lossy digitalzoom.

However, this embodiment enables an omission of a complex optical zoomat the image acquisition unit. The digital zoom has the further effectthat also when modifying the magnification and/or the image section thatis currently displayed by the image display unit, the illuminationconditions and the contrast characteristics of the overall image arekept constant. This again results in simplifications on the part of theimage acquisition unit.

According to a further exemplary embodiment of the observation device,the image acquisition unit is configured to detect image data of a rawdata pixel quantity that is greater than the recording pixel quantity,wherein the raw data pixel quantity corresponds to an overallacquisition range of the image sensor, and wherein the recording pixelquantity is a selected section of the raw data pixel quantity. Thisarrangement has the effect that a boundary region of the overallacquisition range does not necessarily have to be selected for theprovision of the recording area. In the boundary region of imagesensors, often adverse optical effects are present, for instancedistortions, contrast variations, blurs and such like. It is insofarbeneficial that a further processing of the area involved is omitted.

A further benefit of the above-mentioned arrangement may be present whenusing an image acquisition unit that is configured for stereo detectionand that provides two respective image sensors. When the overallacquisition range of at least one of the two image sensors is greaterthan the area that is respectively selected as recording area, a lateraldistance between the both half images that eventually form the stereoimage may be modified. This may be used for stereoscopic visualization.For modifying the offset between the half images, no mechanical oroptical manipulation is necessary. Rather, the respective recording areamay be displaced accordingly in the overall acquisition range.

According to a further exemplary embodiment of the observation device,the control unit is configured to provide haptic feedback at the inputmodule, for instance when reaching limit values or extreme values ofparameter ranges that are controllable by the input module.

In this way, the input module for instance may comprise a so-calledforce feedback function. It may be envisaged to provide vibrationgenerators or similar actuators at the input module, and to couple thesame with the actuation element, for instance. The haptic feedback hasthe effect that the feedback may take place by the tactile perception ofthe operator, namely directly at the hand by means of which the operatoractuates the input module. In this way, no considerable optical and/oracoustical distraction is present.

By way of example, the haptic feedback may be used to signal to theoperator that a maximum zoom stage has been reached. A further examplefor the haptic feedback involves entering a boundary region of therecording area when “displacing” the display areas in the recordingarea.

According to a further exemplary embodiment of the observation device,the image processing unit is configured to generate overview images thatrepresent an area that basically corresponds to an area that is coveredby the recording pixel quantity, wherein the overview images comprise anoverview pixel quantity that is selected to be smaller than the displaypixel quantity, wherein the overview images are displayable by the imagedisplay unit, at least temporarily parallel to the display images, andwherein the overview images at least sectionally overlay the displayimages. In this way, for instance a picture-in-picture function may beprovided. Hence, visual navigation may be simplified. The overviewimages may be arranged to be semi-transparent. It goes without sayingthat the overview images do not have to be constantly shown. It may beenvisaged to show the overview images when the operator actuallyoperates the input module. This may for instance relate to adisplacement of the display area or a modification of the magnification.It is beneficial in these cases to show the overview image.

It goes without saying that separate input elements may be formed at theinput module, for instance buttons, switches and such like to show orfade out the overview image on demand.

According to a refinement of the above mentioned embodiment, the imagedisplay unit is configured to highlight a section area in the displayedoverview image that indicates an area that is covered by the displaypixel quantity within the recording pixel quantity, wherein the sectionarea is moved in the overview images when the area that is covered bythe display pixel quantity is moved in the area that is covered by therecording pixel quantity, due to an actuation of the control element. Inthis way, positioning may be even further simplified.

According to a further exemplary embodiment of the observation device,at least the image acquisition unit and the input module of the controlunit are autoclavable. In this way, a sterilization of these componentsmay easily take place. This is for instance in the context of medicaloperations a substantial benefit.

In regard of the input module, it is provided in at least some exemplaryembodiments that the detection of the actuation movements takes place bya detection of deformations of the actuation element. Accordingly, theinput module that is provided with the actuation element may beintegrally shaped and for instance provided with only a small number ofdistinct components that are movable with respect to one another. Inthis way, the input module is robust and suitable for severalsterilization procedures, for instance.

A further exemplary embodiment and/or operation mode of the observationdevice involves an assignment of an action, for instance of a functionto be controlled, to a plurality of degrees of freedom and/or actuationaxes of the actuation element. For instance, a zoom-function may becontrolled both by a rotation (using the rotation direction) and by apull/push movement (using the translational direction). In this way, aredundant operation is enabled. It may be envisaged to assign theassigned degrees of freedom in consideration of a defined hierarchy orpriority to the functions so that the operation still may be performedin an unambiguously and intuitive fashion. This may for instance relateto a temporary change of the assignment. It may be further envisaged toeffect in this way a coarse adjustment and a fine adjustment, wherein adegree of freedom is assigned to the coarse adjustment and anotherdegree of freedom is assigned to the fine adjustment. This may forinstance relate to the zoom-function or the focus drive. Generally, thedifferent degrees of freedom may be different from one another in termsof the sensitivity of the adjustment/actuation.

A further exemplary embodiment and/or operation mode of the observationdevice involves the definition of preferred functions, whereinaccordingly assigned actuations are detected and assessed with highpriority. Low priority (subordinate) actuations that may be assigned tofunctions that are not preferred functions may here be ignored. In otherwords, defined functions may be blocked so that actuations that areapplied via the respective degrees of freedom do not result inrespective activities. This may simplify defined actions as undesiredactuations of other functions may be avoided. For instance, in someoperation modes, a safe decoupling of the zoom-function from the focusdrive and/or from a displacement of the image section may take place.

According to a further exemplary embodiment of the observation device,the control unit is provided with a mounting feature comprising a quickrelease coupling for releasably mounting the control unit to a holder orstand.

According to a further exemplary embodiment of the observation device,the control unit is arranged to be covered with a sterile cover, whereinthe input module is arranged to be actuated through the sterile cover.

Further, a similar quick release coupling between the image acquisitionunit and the stand may be provided. Preferably, the image acquisitionunit and the control unit use the same or similar mounting features fora releasable attachment or mounting to a holder or stand. The imageacquisition unit and the control unit can be attached to the sameholding system.

In regard of the use, these and other objects are achieved by a use of amulti-axis input module, for instance a single-hand operable inputmodule, in a control unit of a medical observation device forcontrolling image acquisition parameters and display parameters, whereinthe observation device comprises an image acquisition unit for providingrecorded images of a predefined recording pixel quantity and an imagedisplay unit for displaying display images of a predefined display pixelquantity, wherein the input module comprises plurality of actuationaxes, wherein one actuation axis is arranged to be used for selecting amagnification mode, and at least two actuation axes are arranged to beused for moving an area that corresponds to the display image quantity,in consideration of a current magnification mode, in an area thatcorresponds to the recording pixel quantity.

Also in this way the object of the invention is perfectly achieved.

In certain embodiments, the observation device is refined in accordancewith at least one of the aspects described herein. In certainembodiments, the input module is arranged in accordance with at leastone of the aspects mentioned herein.

It is to be understood that the previously mentioned features and thefeatures mentioned in the following may not only be used in a certaincombination, but also in other combinations or as isolated featureswithout leaving the spirit and scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the disclosure are disclosed by thefollowing description of a plurality of exemplary embodiments, withreference to the drawings, wherein:

FIG. 1 is a schematic lateral view of an embodiment of an observationdevice;

FIG. 2 is a perspective top view of an image acquisition unit that isarranged as an exoscope;

FIG. 3 is a further perspective view of the arrangement according toFIG. 2 in a different orientation;

FIG. 4 is a perspective top view of an arrangement of a single-handinput module;

FIG. 5 is a perspective top view of a further arrangement of asingle-hand input module;

FIG. 6 is a perspective view of yet a further arrangement of asingle-hand input module;

FIG. 7 is a schematic view of a recorded image;

FIG. 8 is a schematic view of a display image;

FIG. 9 is a schematic view of a display image that covers an area thatcorresponds to an area of a recorded image;

FIG. 10 is a schematic view of a display image that overlays a recordedimage, for illustrative purposes, wherein a display image area covers aportion of the area of the recorded image;

FIG. 11 is a further view in accordance with FIG. 10, wherein thedisplay image covers a display area in the recording area of therecorded image having a pixel quantity that is smaller than the pixelquantity of the display area;

FIG. 12 is a further view of a recorded image, wherein an overallacquisition range is indicated which is greater than a recording area ofthe recorded image;

FIG. 13 is a schematic view of an input module and a display image whichoverlays a recorded image, for elucidating a position control;

FIG. 14 is a further view that is similar to FIG. 13 for elucidating azoom function;

FIG. 15 is a schematic simplified view of an input module and an imageacquisition unit for elucidating a focus setting;

FIG. 16 is a further schematic comparison of a recorded image and adisplay image for elucidating a picture-in-picture function;

FIG. 17 is a schematic lateral view of a further embodiment of anobservation device; and

FIG. 18 is a schematic lateral view of an arrangement of a single-handinput module that is covered with a sterile cover.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG. 1 schematically illustrates an exemplary configuration of anobservation device 10 that is arranged in accordance with at least someaspects of the present disclosure. The observation device 10 comprisesan optical instrument 12. By way of example, the optical instrument isarranged as an exoscope. Alternative embodiments may be envisaged,wherein the optical instrument is arranged as endoscope. The opticalinstrument 12 is illustratively mounted to a stand 14 which may also bereferred to as mounting arm. Accordingly, a fixed orientation of theoptical instrument 12 with respect to an object to be observed, forinstance a body part or an organ of a patient, is present.

The observation device 10 further comprises an image display unit 16involving at least one display and/or one screen 24. Both the opticalinstrument 12 and the image display unit 16 may be arranged asstereoscopic devices. Accordingly, the optical instrument 12 may bearranged to capture right and left half images, wherein the imagedisplay unit 16 is configured to display the right and left half imagesin a desired fashion to generate a stereoscopic (spatial) impression foran observer. Generally, each half image comprises a completerepresentation of the observed object, wherein an offset or an offsetangle may be present between the representations of the right and lefthalf images. In this way, the spatial impression may be generated. Theimage display unit 16 may further comprise so-called 3D glasses, HMDglasses (head-mounted display) and similar devices.

The optical instrument 12 comprises an image acquisition unit 18. Forinstance, the image acquisition unit 18 is integrated in the opticalinstrument 12 and preferably arranged at the distal end thereof. Theobservation device 10 further comprises an image processing unit 20. Theimage processing unit 20 may generally be arranged as a centralizedimage processing unit or a decentralized (distributed) image processingunit. By way of example, FIG. 1 illustrates an arrangement, wherein theimage processing unit 20 comprises sections 20-1 and 20-2. The (part)image processing unit 20-1 is associated with the optical instrument 12.The (part) image processing unit 20-2 is, for instance, shown in aseparated state and arranged herein as a separate component. It goeswithout saying that the (part) image processing unit 20-2 may also be atleast partially integrated in the image display unit 16 (at least in astructural sense).

Generally, the image processing unit 20 is interposed between the imageacquisition unit 18 and the image display unit 16 to process and prepareimage data that is provided by the image acquisition unit 18 to supplythe data to the image display unit 16 for visualization.

The image acquisition unit 18 comprises at least one image sensor 26that is arranged to observe a defined object plane 28 and to convert thedetected optical signals in electrical (data) signals. A second imagesensor (not explicitly shown FIG. 1) enables a stereoscopic imaging. Afield of view of the image sensor 26 is indicated in FIG. 1 by 30. Theobject plane 28 of the optical instrument 12 that is illustrativelyarranged as an exoscope is in accordance with FIG. 1 spaced away fromthe image sensor 26, for instance from an objective of the image sensor26. An exoscope is generally used at an object distance (workingdistance) in the range of about 250 mm to about 750 mm. The image sensor26 comprises a CCD sensor, for instance.

The optical instrument 12 shown in FIG. 1 is not configured to beinserted in body orifices and/or further narrow passages. However, theobservation device 10 according to alternative arrangements comprises aninstrument 12 that is arranged as an endoscopic instrument and that isconfigured to be inserted in body orifices.

The image acquisition unit 18 further comprises an illumination unit 32.The illumination unit 32 may be integrated in the instrument 12. It maybe however also envisaged to couple external light sources to theinstrument 12 to provide an illumination for the object plane 28 in theregion of the image acquisition unit 18.

Further, an erecting unit or image erection 34 is associated with theimage acquisition unit 18. The image erection 34 involves, for instance,a motor-powered or manually actuable erection that rotates the at leastone image sensor 26 about the longitudinal axis of the objective and/orthe optical axis. In the event that two image sensors as in the presentexample are provided, both image sensors 26-1 and 26-2 are togetherrotated about an axis that is perpendicular to a stereo basis, whereinthe axis is centered between the image sensors. In this way, theorientation (rotation orientation) of the detected image may becontrolled.

The optical instrument 12 further comprises a shaft 40. At the proximalend of the shaft 40 that is facing away from the distal end, a handlehousing 42 is formed. The optical instrument 12 is basically alsoarranged as a manually guidable instrument. Accordingly, the instrument12 may be grasped and guided at the handle housing 42. Nevertheless, afixed mounting to the stand (mounting arm) 14 is beneficial for avariety of applications.

The optical instrument 12 further comprises an interface 44 at theproximal end thereof that is, for instance, arranged as data interfaceor communication interface. Via the interface 44, image data may betransferred. The optical instrument 12 may further be supplied withcontrol commands by the interface 44, which may be for instancegenerated by the control unit 22 and/or transferred by the external(part) image processing unit 20-2.

The image processing unit 20 that is illustrated in FIG. 1 as adistributed unit illustratively comprises a first processing module 46and a second processing module 48. The first processing module 46 isassociated with the instrument 12 and coupled with the image acquisitionunit 18. The second processing module 48 is arranged as an external orseparate processing module.

The observation device 10 further comprises a control unit 22 which willbe described in more detail hereinafter. The control unit 22 is arrangedto be mediately or directly coupled with the image acquisition unit 18,the image processing unit 20 and/or the image display unit 16.

The control unit 22 illustratively comprises an input module 50 whichis, for instance, arranged as single-hand operable input module. Theinput module 50 comprises an actuation element 52, preferably asingle-hand actuation element. The actuation element 52 is for instancepuck-shaped, dome-shaped or button-shaped and/or disc-shaped. In certainembodiments, the actuation element 52 comprises a size allowing anoperator to encompass the actuation element 52 with the hand, comparableto a computer mouse. Accordingly, the actuation element 52 of the inputmodule 50 shown in FIG. 1 comprises a diameter of at least 30 mm(millimeter), preferably a diameter of at least 40 mm, further preferreda diameter of at least 50 mm. In this way, the actuation element 52 mayalso be grasped and actuated in a reliable and repetitive fashion whenusing gloves. For instance, the input module 50 comprises furtheractuation elements 54 arranged as buttons and such like in addition tothe actuation element 52. In this way, additional functions may beprovided.

In FIG. 1, lines that are designated by 56-1, 56-2, 56-3 and 56-4illustrate that the components of the observation device 10 maygenerally communicate with one another may be in a direct or mediateway. It goes without saying that at least some of the lines 56-1, 56-2,56-3 and 56-4 may be arranged at wireless connections. It may be furtherenvisaged that the components of the observation device 10 are coupledwith a common communication switch and that, as a result, a star-shapedtopology is present. Other types, for instance bus systems and such likemay be envisaged.

By way of example, the display 24 of the image display unit 16illustrates organs of a patient. The image display unit 16 is arrangedto illustrate a display image 60 that is based on a recorded image (notseparately shown in FIG. 1) that is provided by the image acquisitionunit 18. An overview image 62 may at least sectionally and at leasttemporarily overlay the display image 60, for instance similar to apicture-in-picture representation. The overview image 62 exemplarilyelucidates a total area that may be detected by the image acquisitionunit 18, wherein the display image 60, depending on the selectedmagnification, illustrates the total area or sub portions thereof.Accordingly, the overview image 62 facilitates orientation and/ornavigation.

With reference to FIGS. 2 and 3, an exemplary arrangement of an opticalinstrument 12 that is arranged as an exoscope is further elucidated. Theoptical instrument shown in FIGS. 2 and 3, in terms of the basicstructure, corresponds basically to the optical instrument 12 accordingto FIG. 1.

The optical instrument 12 comprises a shaft 40, wherein a detector head64 is arranged at the distal end thereof. The detector head 64accommodates the image acquisition unit 18, at least parts thereof. Atthe proximal end of the shaft 40 that is facing away from the distalend, a handle housing 42 is formed with may accommodate furthercomponents of the optical instrument 12.

FIG. 3 illustrates that the optical instrument 12 is illustrativelyarranged as a stereoscopic instrument. Accordingly, the imageacquisition unit 18 comprises in the region of the detector head 64 afirst image sensor 26-1 and a second image sensor 26-2. Accordingly, twodetector beam paths are present. First detector optics 66-1 isassociated with a first detector beam path. Second detector optics 66-2is associated with a second detector beam path. Further, illuminationoptics designated by 68, that is associated with the illumination unit32, is shown in FIG. 3.

In an exemplary arrangement, the interface 44 (FIG. 1) of the opticalinstrument 12 is further configured to be coupled with a light guideand/or an external light source. Accordingly, the illumination unit 32(refer to FIG. 1) does not necessarily have to be arranged as an activeillumination. Rather, the illumination unit 32 may involve light guidesextending between the proximal end and the distal end through the shaft40 and leading to the illumination optics 68.

With reference to FIGS. 4, 5 and 6, several exemplary arrangements ofinput modules 50 that may be used at the control unit 22 will beelucidated hereinafter. It goes without saying that single aspects ofone of the input modules 50 shown in FIGS. 4, 5 and 6 may also beincorporated in the other input modules.

A first arrangement of an input module 50 that is arranged forsingle-hand operation is shown in FIG. 4. The input module 50 comprisesa main actuation element 52 that is for instance puck-shaped. Theactuation element 52 is mounted to a basis 72 of the input module 50.Further, for instance, additional (secondary) actuation elements 54 areprovided, for instance switches, buttons and such like. In FIG. 4 thereis further a communication interface designated by 74 by means of whichcontrol signals may be provided which may be generated due to actuationsof the actuation elements 52, 54.

In certain embodiments, input modules 50 in the context of the presentdisclosure are arranged as multi-axis input modules, for instance asfour-axes input modules. An exemplary assignment of movement axes and/oractuation axes to the input module 50 is elucidated in FIG. 4. FIG. 5illustrates an alternative assignment.

In FIG. 4, a translational direction is elucidated by a double arrowthat is designated by 80. A rotation direction 82 that indicates arotation about the axis of the translational direction 80 is illustratedby a curved double arrow designated by 82. Accordingly, the actuationelement 52 may be translationally actuated (pulling and pushing). Inaddition, also a rotation actuation is enabled (turning).

Further actuation directions are identified in FIG. 4 by 84 and 86 whichdesignate respective double arrows. The actuation directions 84, 86 mayalso be referred to as sliding directions. The sliding directions 84, 86span a plane in which the actuation element 52 may be movedperpendicular to the translational direction 80. For instance, theactuation element 52 may be at least partially laterally deflected togenerate a displacement signal.

By way of example, the axes of a coordinate system that is defined bythe actuation directions 80, 84, 86 are designated by X (confer 86), Y(confer 84) and Z (confer 80). It goes without saying that thisassociation primarily serves illustrative purposes. Modifications may beenvisaged without further ado. The skilled person may easily applynecessary conceptual transformations. To enable the movements, using thedegrees of freedom and/or the movement directions 80, 82, 84, 86, theactuation element 52 is mounted to the basis 72 in a fashion movablewith respect to the basis 72, at least in defined limits. By way ofexample, optical sensors may be provided to detect the deflections andto assign the deflections to the respective axes.

In certain embodiments, input modules 50 presented in the context ofthis disclosure are arranged as input modules comprising hapticfeedback. In this way, feedback may be provided to an operator thatactuates the input module 50. By way of example, the haptic feedback isgenerated by a vibration motor or vibration generator 88 that isassociated with the input module 50, for instance with the actuationelement 52. The haptic feedback may for instance signal when limitvalues or extreme values are reached. In this way, it may be signaled toan operator that certain ranges or limit values may not be exceeded.

It may also be envisaged to provide a plurality of vibration generators88 that are associated with at least some of the actuation directionsand/or axes 80, 82, 84, 86. In this way, an even more sensitive anddetermined feedback may be provided.

FIG. 5 illustrates an alternative exemplary arrangement of an inputmodule 50 for a control unit 22 that may be used at the observationdevice 10 according to FIG. 1. The input module 50 comprises adisc-shaped or cylindrical actuation element 90 which may be basicallyarranged similar to the actuation element 52. The actuation element 90is supported at a basis 92 and connected with the basis 92 via a shaft94. In terms of the movement axes and/or the actuation axes, the inputmodule 50 elucidated with reference to FIG. 5 is modified with respectto the arrangement elucidated with respect to FIG. 4. As alreadyillustrated in FIG. 4, a translational direction 80 and a rotationdirection 82 is provided, wherein the rotation direction 82 indicatesrotations about the translational direction 80. Instead of the slidingdirections 84, 86 (confer FIG. 4), the arrangement according to FIG. 5comprises swivel directions 98, 100 that represent respectivedeflections and/or pivot movements of the actuation element 90 about theX-axis and/or the Y-axis. Also by means of such an actuation movement, arespective signal may be generated that may represent a displacement ina two-dimensional space.

The actuation element 90 according to FIG. 5 is fixedly mounted to thebasis 92. In other words, the actuation element 90 is not movablymounted to the basis 92. However, the actuation element 90 issectionally deflectable and/or movable as for instance the shaft 94 isnot arranged in an infinitely stiff fashion. In this way, defineddeformations at the shaft 94 may be generated. The deformations may forinstance involve compressions, stretching, deflections and/or twisting.Deformations of that kind may be detected by means of sensors 96, forinstance by a plurality of respective sensors. By way of example, thesensors 96 may be arranged as strain gauges. Hence, even minimumdeformations at the shaft 94 may be detected and assigned to theactuation directions 80, 82, 98, 100. The actuation element 90 accordingto FIG. 5 may also be coupled with an appropriate vibration generator 88to provide haptic feedback.

The embodiment of the input module 50 elucidated with reference to FIG.5 is integrally shaped as the actuation element 90 is fixedly coupledwith the basis 92. In this way, the input module 50 is considerablyrobust. This may simplify cleaning procedures, for instance disinfectionprocedures and/or sterilization procedures. Hence, the input module 50may easily be sterilized in an autoclave.

FIG. 6 elucidates a further arrangement of an input module 50 that isarranged for single-hand operation and that may be used at the controlunit 22. The input module 50 comprises an actuation element 104 that isarranged basically similar to the actuation element already elucidatedwith reference to FIG. 4. The input module 50 further comprises a basis108, wherein a hand rest 106 is formed at the basis 108. Further aplurality of additional actuation elements 54, for instance buttons,switches and such like is provided at the basis 108.

With reference to FIG. 7 and FIG. 8, fundamental functions of the imageacquisition unit 18 and the image display unit 16 will be explained inmore details. FIG. 7 shows a recorded image 58 which can be detected andprovided by the image acquisition unit 18. FIG. 8 shows a display image60 which can be displayed by the image display unit 16. It is assumedhereinafter that the recorded images 58 and the display images 60correspond to an image channel of a stereoscopic representationcomprising two image channels, or two a (single) image channel of anon-stereoscopic representation. An extension to stereoscopic data maybe envisaged without further ado.

The recorded image 58 according to FIG. 7 comprises a magnitude ofpixels 110. A pixel quantity of the recorded image 58 will be referredto as n_(a). Dimensions of the recorded image 58 are indicated in FIG. 7by w_(a) and h_(a). The width of the recorded image 58 is designated byw_(a) and involves a defined plurality of pixel columns c_(a). Theheight of the recorded image 58 is designated by h_(a) and comprises adefined number of pixel lines r_(a).

The recorded image 58 covers a recording area 112. The recording area112 basically corresponds to the area of the object plane 28 (conferFIG. 1) which is basically detectable with the image sensor 26 (however,confer the further explanations in connections with FIG. 12).

The display image 60 shown in FIG. 8 comprises a multitude of pixels120. A pixel quantity of the display image 60 is n_(b). Dimensions ofthe display image 60 are indicated in FIG. 8 by w_(b) and h_(b), whereina width is designated by w_(b) and a height is designated by h_(b). Thewidth w_(b) comprises a defined number of pixel columns c_(b). Theheight h_(b) comprises a defined number of pixel lines r_(b). The pixels120 of the display image 60 define a display area 122.

In certain embodiments, the pixel quantities n_(a) and n_(b) are definedso that the pixel quantity n_(a) of the recording area 112 is an integermultiple of the pixel quantity n_(b) of the display area 122. By way ofexample, the display area 122 may be arranged as HD area (1280×720pixels) or as Full HD area (1920×1080 pixels). Accordingly, therecording area 112 may comprise two times, three times, four times, sixtimes or even eight times the number of pixels of the display area 122.

In certain embodiments, the aspect ratio (c_(a):r_(a)) of the recordingarea 112 corresponds to the aspect ratio (c_(b):r_(b)) of the displayarea 122.

The checkered illustration and/or square illustration used forindicating the recorded images 58 and/or the display images 60elucidates corresponding pixel quantities n_(a) and/or n_(b). Acomparison of FIG. 7 with FIG. 8 shows accordingly that the display area122 that is displayable by the display image 60 corresponds merely to asubportion of the recording area 112 when the (detail) resolution orpixel density is maintained, i.e. when a contiguous area of the pixels110 of the recording area 112 shall be illustrated in the display area122. Accordingly, dimensions w_(b), h_(b) of the display areas 122 are,in terms of the object plane 28, smaller than the dimensions w_(a),h_(a) of the potentially available recording area 112.

FIG. 9 elucidates a representation mode, wherein the display image 60represents the entire recording area 112 of the recorded image 58.Accordingly, the display area 122 basically corresponds to the recordingarea 112. However, the pixel density is significantly smaller as only alimited number of pixels 120 is available in the display area 122. Inother words, for instance, only each second or only each fourth of thepixels 110 of the recording area 112 is used for the representation inthe display area 122. It goes without saying that also a respectiveaverage of neighboring pixels may be used to convert the pixel quantityn_(a) of the recording area 112 to the pixel quantity n_(b) of thedisplay area 122. Accordingly, the representation in FIG. 9 is morecoarsely screened than the representation in FIG. 7. In FIG. 9, c_(a)′and h_(a)′ represent a number of columns and/or a number of lines thatare derived from the original values c_(a) and h_(a) that correspond inthis example to the values of c_(b) and h_(b), respectively.

FIG. 10 shows a representation mode, wherein the display image 60 isused for displaying merely a section of the recorded image 58. Comparedto FIG. 9, the display image 60 of FIG. 10 does not show the entirerecording area 112. In other words, the dimension of the display area122 c_(b), r_(b) is smaller than the dimension c_(a), r_(a) of therecording area 112. In contrast to the representation according to FIG.9, for the representation according to FIG. 10 a greater number ofpixels or all the pixels in the selected section of the recording area112 are illustrated in the display area 122. Depending on the selectedmagnification, for instance a 1:1 representation of at least a subset ofthe pixels 110 of the recording area 112 may be present in the displayarea 122. FIG. 9 shows an overview without magnification. FIG. 10 showsan intermediate magnification stage, wherein a section of the recordedimage 58 is represented in the display image 60, wherein the section isselected in this magnification stage such that a contiguous subset ofthe pixels 110 of the recording area 112 forms the pixels 120 of thedisplay area 122, refer in this context also to the illustration of FIG.16, wherein the recorded image 58 and the display image 60 areseparately shown for a better understanding.

FIG. 11 elucidates a further magnification stage wherein an even smallersection 126 of the recording area 112 is represented in the display area122. The section 126 extends in the recording area 112 over a definednumber of pixels n_(c) that is defined by a defined number of pixelcolumns c_(c) and a defined number of pixel lines r_(c). The pixelquantity n_(c) of the section 126 is smaller than the pixel quantityn_(b) that can be displayed in the display area 122 (refer to theillustration of the section 126 in FIG. 11, wherein for illustrativepurposes the greater (display) pixel quantity n_(b) overlays the smaller(sensor) pixel quantity n_(c)). In other words, a plurality of displaypixels may correspond to a recording pixel. Accordingly, aninterpolation and/or computational “upscaling” takes place to obtain thepixels 120 (pixel quantity n_(b)) of the display image 60 based on thelimited pixel quantity n_(c).

In this way, a greater magnification than for instance in themagnification mode according to FIG. 10 may be achieved, wherein themagnification is no longer loss-free. FIG. 10 shows a loss-freemagnification. Depending on the ration between the number of pixelsn_(a) of the recording area 112 and the number of pixels n_(b) of thedisplay area 122, at least two loss-free representation stages and/ormagnifications (refer to the overview representation in FIG. 9 and themagnification in FIG. 10) or even three, four, or even more loss-freemagnification stages may be provided.

It goes without saying that also appropriate intermediate stages may bedisplayed, if desired. Respective interpolations may be applied. If arepresentation is desired that extends beyond the magnification shown inFIG. 10 (1:1-representation), interpolation procedures have to beapplied. However, it has been observed that the resulting display images60 are sufficiently detailed when the defined pixel quantity n_(b), thatis provided in the display area, is sufficiently large, for instanceFull HD. A 1:1 representation (one-to-one representation) is providedwhen the pixel quantity in the selected section 122 in the recordingarea 112 corresponds exactly (or at least substantially) to the pixelquantity in the display area 122.

FIG. 12 elucidates a further exemplary arrangement, for instancerelating to the image acquisition unit 18 and/or the at least one imagesensor 26. By way of example, FIG. 12 elucidates a recorded image 58 anda selected display image 60 in the recorded image 58. The at least oneimage sensor 26 may basically be arranged to detect image data in anoverall acquisition range 130 that is greater than the recording area112 of the recorded image 58. For instance, a frame may be provided thatoverlaps the recording area 112. By way of example, the overallacquisition range 130 covers a raw data pixel quantity n_(r) that isgreater than the pixel quantity n_(a) of the recording area 112.

The recording area 112 may be for instance selected in the overallacquisition range 130 such that an integer ratio between the pixelquantity n_(a) of the recording area 112 and the pixel quantity n_(b) ofthe display area 122 is ensured. A further feature may involve that therecording area 112 may be deliberately selected to be smaller than theoverall acquisition range 130 to avoid disturbing effects that are oftenpresent in boundary regions of image sensors 26.

A further feature of the arrangement elucidated with reference to FIG.12 may be present in regard of the stereoscopic image processing andimage representation. The section of the overall acquisition range 130that forms the recording area 112 of the image sensor 26 may bedisplaced, at least within narrow bounds. This may be beneficial foradjustment and/or fine tuning of the image acquisition unit 18. Further,when using two image sensors 26 that are capturing half images for thestereoscopic representation, a desired image distance between the halfimages may be adjusted by displacing the recording area 112 in theoverall acquisition range 130. In this way, adjustment and fine tuningmay be performed by means of software. In certain embodiments, in doingso, complex mechanical and/or optical adjustment tasks may be omitted.

With reference to FIGS. 13, 14 and 15, a beneficial assignment ofactuation axes of the input module 50 for controlling image acquisitionparameters and/or display parameters will be elucidated.

FIG. 13 shows a display image 60 that covers a display area 122 that isselected as a subset of the recording area 112 of the recorded image 58.The display area 122 may be displaced within the boundaries that aredefined by the recording area 112, refer to arrows in FIG. 13 that aredesignated by X and Y. This sliding movement may be effected via thesliding directions 84, 86 of the input module 50. However, a respectivedisplacement may also be controlled by the swivel directions 98, 100,refer to FIG. 5 in this context. Displaced display areas are designatedin FIG. 13 by 140, 142.

FIG. 14 elucidates a zoom function, wherein areas of the recorded image58 having a different size are selected to define the display area 122based on which the display image 60 is derived.

A smaller section is designated by 150. The smaller section results inthe generated display image in a magnification. A greater section isindicated by 152. The section 152 results in the represented displayimage in a reduction. A double arrow indicated by 154 elucidates thescaling of the display area 122 for generating different magnificationstages.

The scaling may be achieved by an actuation of the input module 50 inthe translational direction 80, i.e. by pushing or pulling the actuationelement 52.

FIG. 15 elucidates a focus adjustment that may basically be provided inaddition to the displacement according to FIG. 13 and to themagnification adjustment according to FIG. 14 by the input module 50.For instance, the image acquisition unit 18 comprises a focus driveand/or a focus adjustment. The view field 30 and/or the aperture angleof the view field 30 anyway are not easily adjustable in arrangementsthat do not comprise an optical zoom. However, the distance of a focusplane (also: focal plane) 160, 162, 164 having a sufficiently sharprepresentation may be modified by the image acquisition unit 18 tosharpen objects having a different distance to the image acquisitionunit 18. In other words, an object that is in the foreground or anobject that is in the background may be selectively sharpened. Arespective displacement of the focus plane is indicated in 15 by adouble arrow designated by 166. To this end, focus lenses in the opticalinstrument may be displaced. The displacement may be controlled by theinput module 50.

By way of example, the sharpness adjustment may be effected by an actionin the rotation direction 82. To this end, the actuation element 52 maybe rotated about its longitudinal axis.

It is understood that also alternative arrangements may be envisaged,wherein for instance the magnification adjustment may be effected byrotating the actuation element 52 and the adjustment of the focus planemay be effected by pulling and/or pushing the actuation element 52.

The functions elucidated with reference to FIGS. 13, 14 and 15 eachcomprise a defined adjustment range. When limit values and/or extremeconditions are reached, haptic feedback may be provided at the inputmodule 50 to signal this condition to the operator. By way of example,when displacing this section according to FIG. 13, approaching theboundary of the recording area 112 may be signaled. With the functionshown in FIG. 14, for instance, haptic feedback may signal that theselected display area 122 corresponds to the recording area 112 and thatconsequently no smaller zoom stage is enabled. By contrast, it may besignaled that an extreme magnification (extremely small display area122) is selected and that no further magnification is possible.

Similarly, also with the focus plane adjustment according to FIG. 15,feedback may be provided when a minimum distance or a maximum distanceis achieved.

FIG. 16 elucidates a further exemplary function that may be provided bythe observation device. As already described further above, FIG. 16illustratively shows a recorded image 58 and a display image 60 that isformed based on a section of the recorded image 58 that defines adisplay area 122. The display image 60 covers the display area 122.According to at least some arrangements, it may be envisaged to displayan overview image 62 in the display image 60, at least temporarily, thatat least partially overlays the display area 122. This may be, forinstance, implemented as picture-in-picture representation. In certainembodiments, the overview image 62 covers the entire recording area 112,even though in a coarsely screened representation. In this way, anoptical orientation aid may be provided to the operator. Preferably, inthe overview image 62 there is further indicated a section area 172which is used as a position indicator. The section area 172 indicatesthe position of the selected display area 122 in the recording area 112of the recorded image 58.

It may be envisaged to show the overview image 62 at least in situationswhen one of the functions illustrated in FIG. 13, 14 or 15 is used. Ifdesired, the overview image 62 may also be displayed and faded out atthe push of a button. The overview image 62 may be at least partiallytransparent to make an underlying area of the display area 122 at leastpartially visible.

The functions elucidated with reference to FIGS. 13, 14 and 15illustrate that the input module 50 may be used to control imageacquisition parameters and display parameters. This may take placesimultaneously. By way of example, the current position of the focusplane is an image acquisition parameter. By way of example, a currentlyselected magnification stage or a current position of the selected imagesection (display area) in the potentially available recording area is adisplay parameter.

It goes without saying that the recorded image 58 that is shown in someof the figures illustrated herein is not necessarily visible. Rather,the recorded image 58 may be provided in the form of a respective datarepresentation. By way of example, it may be envisaged that therecording area is constantly observed, at a selected frame rate, and, asa consequence, potentially available. Hence, the image acquisition unit18 may provide a recording data stream that may be exploited, entirelyor partially, to derive desired display images.

FIG. 17 is a schematic lateral view of a further embodiment of anobservation device. In FIG. 17, an articulated holder 180 is shown. Theholder 180 comprises, for example, an arm 182 to which a further arm 184is mounted. The arms 182, 184 may also be referred to as columns orlinks. The holder 180 is merely partially shown in FIG. 17. Generally,the holder 180 may be referred to as stand or rack.

A carriage 186 is movably mounted at the arm 184. The arm 184 is movablemounted at the arm 182. Hence, the holder 180 may be provided with apositioning drive designated by reference numerals 190, 192 (indicatingmovement directions between the arms 182, 184, and the arm 184 and thecarriage 186, respectively). At the carriage 186, an optical instrument12 including an image acquisition unit 18 is releasably attached to theholder 180. Hence, the positioning drive 190, 192 may be operated tomove the image acquisition unit 18.

In certain exemplary embodiments, the positioning drive 190, 192 mayalso be controlled by the input module 22, particularly the input module50 thereof. In this way, an adjustment of a detection area of the imageacquisition unit 18 is provided. As the input module 50 is, in at leastsome embodiments, a multi-axis input module, several movement axes ofthe positioning drive 190, 192 may be controlled simultaneously.

For releasably and accurately attaching the optical instrument 12 to theholder 180, a mounting interface 200 is provided. In certain exemplaryembodiments, the mounting interface 200 involves a quick-lock mountingfeature. The mounting interface 200 comprises a socket 202 that isprovided with a recess 204. Further, a mounting bracket 206 is providedthat comprises a mounting protrusion 208. In the exemplary embodimentillustrated in FIG. 17, the socket 202 is assigned to the carriage 186.Further, the mounting bracket 206 is arranged as a holder for theoptical instrument 12. The mounting bracket 206 may be arranged as aclamp holder. Preferably, the mounting interface 200 comprises a lockingfeature that is actuated by a locking actuator 210. For attaching theoptical instrument 12 to the holder 180, the mounting protrusion 208 isinserted into the recess 204, and locked therein, confer a respectivemounting movement direction 212 in FIG. 17. The locking actuator 210 maycontrol a locking feature, for example, a positive locking feature, aforce-fit locking feature, etc. The locking actuator 210 is arranged todisengage and, if necessary, to engage the recess 204 and the mountingprotrusion 208.

In the exemplary embodiment illustrated in FIG. 17, the input unit 22,particularly the input module 50 comprising the actuation element 52, isalso attached to the holder 180. For instance, the input unit 22 isattached to an arm 218 that is mounted to the arm 182. In thealternative, the input unit 22 may also be attached to a separate holderor stand. In either case, a mounting interface 220 may be provided forreleasably attaching the input unit 22 to the holder 180. In certainexemplary embodiments, the mounting interface 220 involves a quick-lockmounting feature. The mounting interface 220 comprises a socket 222 thatis provided with a recess 224. Further, a mounting base 226 is providedthat comprises a mounting protrusion 228. In the exemplary embodimentillustrated in FIG. 17, the socket 222 is arranged at the arm 218. Themounting base 226 is arranged at or forms part of the input module 50 ofthe input unit 22. Preferably, the mounting interface 220 comprises alocking feature that is actuated by a locking actuator 230. Forattaching the optical instrument 12 to the holder 180, the mountingprotrusion 228 is inserted into the recess 224, and locked therein,confer a respective mounting movement direction 232 in FIG. 17. Thelocking actuator 230 may control a locking feature, for example, apositive locking feature, a force-fit locking feature, etc. The lockingactuator 230 is arranged to disengage and, if necessary, to engage therecess 224 and the mounting protrusion 228.

In FIG. 17, the mounting interfaces 200, 220 are shown in a partiallydetached state. The mounting interfaces 200, 220 may utilize the samemating elements (recess, protrusion, locking actuator) so thatinterchangeability is possible.

FIG. 18 is a schematic lateral view of an arrangement of an input module22 comprising a single-hand input module 50 that is covered with asterile cover 240. Hence, even in case the input module 50 is notarranged to be autoclaved or otherwise sterilized, on operation inmedical applications is possible. The sterile cover 240 may be adisposable consumable.

The invention claimed is:
 1. An observation device, comprising: an imageacquisition unit comprising at least one image sensor, an image displayunit that is arranged to display image data provided by the imageacquisition unit, an image processing unit for image processingprocedures, and a control unit comprising a multi-axis input module,wherein the image acquisition unit is configured to provide recordedimages having a predefined recording pixel quantity, wherein the imagedisplay unit is configured to display display images having a predefineddisplay pixel quantity, wherein the recording pixel quantity is equal toor greater than the display pixel quantity, wherein image pixels of thedisplay pixel quantity are obtained from the recording pixel quantity,wherein, for providing views having different magnifications, subsets ofthe recording pixel quantity are selected to form the display pixelquantity, wherein the input module is arranged to control imageacquisition parameters and display parameters, wherein the input moduleis arranged to be coupled with the image acquisition unit forcontrolling at least one image acquisition parameter, wherein anactuation element is arranged as four-axis actuation element, wherein anactuation of a first actuation axis defines a magnification and a sizeof an area of the display images in the recorded images that isassociated with the magnification, wherein an actuation of a secondactuation axis defines a focus setting, wherein an actuation of a thirdactuation axis effects a movement of the area that is covered by thedisplay images in an area that is covered by the recorded images, in afirst movement direction, and wherein an actuation of a fourth actuationaxis effects a movement of the area that is covered by the displayimages in the area that is covered by the recorded images, in a secondmovement direction Y that is inclined with respect to the first movementdirection.
 2. The observation device as claimed in claim 1, wherein theobservation device is arranged as a medical observation device, andwherein the at least one sensor is arranged to detect incidentelectromagnetic radiation in at least one of an UV range, a visiblelight range, and a IR range.
 3. The observation device as claimed inclaim 1, wherein the acquisition unit is a stereo-image acquisition unitcomprising two image sensors.
 4. The observation device as claimed inclaim 1, wherein the input module is coupled with the image acquisitionunit and the image processing unit to operate the image acquisition unitfor modifying image acquisition parameters, and to operate the imageprocessing unit for modifying display parameters, wherein the inputmodule is preferably operable in at least a first operation mode and asecond operation mode, wherein in the first operation mode a directcontrol of image acquisition parameters and display parameters isenabled, and wherein in the second operation mode a control ofperipheral functions is enabled.
 5. The observation device as claimed inclaim 4, further comprising a positioning drive for the imageacquisition unit, wherein the input module, in the second operationmode, is operable to control the positioning drive for positioning theimage acquisition unit.
 6. The observation device as claimed in claim 1,wherein the input module is arranged as a single-hand input module andprovided with the actuation element that is manipulable by an operatorand that provides a plurality of degrees of freedom of movement forinputs, particularly at least one translational direction, at least onerotation direction and at least two further degrees of freedom which arearranged as sliding directions or swivel directions.
 7. The observationdevice as claimed in claim 6, wherein the actuation element ispuck-shaped or knob-shaped, wherein the actuation element is coupledwith sensors to detect a pull/push movement along a longitudinal axis ofthe actuation element, a rotation about the longitudinal axis, andsliding movements in a plane Y that is oriented perpendicular to thelongitudinal axis, or swivel movements about pivot axes Y that areoriented perpendicular to the longitudinal axis.
 8. The observationdevice as claimed in claim 1, wherein the actuation element is coupledwith at least one sensor that is configured as a displacement transduceror a force transducer.
 9. The observation device as claimed in claim 1,wherein the first actuation axis provides a translational direction,wherein the second actuation axis provides a rotation direction havingan axis that is parallel to the translational direction, and wherein thethird actuation axis and the fourth actuation axis respectively providea sliding direction, for detecting a lateral deflection perpendicular tothe translational direction, or a swivel direction, for detecting alateral inclination about axes that are oriented perpendicular to thetranslational direction.
 10. The observation device as claimed in claim1, wherein the recording pixel quantity is an integer multiple of thedisplay pixel quantity.
 11. The observation device as claimed in claim1, wherein the image processing unit is configured to provide the imagedisplay unit with a display pixel quantity that is displayedinterpolation-free.
 12. The observation device as claimed in claim 1,wherein the image acquisition unit is arranged to detect image data of araw data pixel quantity that is greater than the recording pixelquantity, wherein the raw data pixel quantity corresponds to an overallacquisition range of the image sensor, and wherein the recording pixelquantity is selected as a section of the raw data pixel quantity. 13.The observation device as claimed in claim 1, wherein the control unitis configured to provide haptic feedback at the input module,particularly when achieving limit values or extreme values of parameterranges that are controlled by the input module.
 14. The observationdevice as claimed in claim 1, wherein the image processing unit isconfigured to generate overview images that represent an area thatbasically corresponds to the area that is covered by the recording pixelquantity, wherein the overview images comprise an overview pixelquantity that is selected to be smaller than the display pixel quantity,and wherein the overview images are displayed by the image display unit,at least temporarily parallel to the display images, wherein theoverview images at least partially overlay the display images.
 15. Theobservation device as claimed in claim 14, wherein the image displayunit is configured to highlight a section area in the displayed overviewimages that indicates an area within the recording pixel quantity thatis covered by the display pixel quantity, and wherein the section areais moved in the overview images when the area that is covered by thedisplay pixel quantity is moved in the area that is covered by therecording pixel quantity by actuating the control unit.
 16. Theobservation device as claimed in claim 1, wherein at least the imageacquisition unit and the input module of the control unit areautoclavable.
 17. The observation device as claimed in claim 1, whereinthe control unit is provided with a mounting feature comprising a quickrelease coupling for releasably mounting the control unit to a holder orstand.
 18. The observation device as claimed in claim 1, furthercomprising a sterile cover, wherein the control unit is arranged to becovered by the sterile cover, and wherein the input module is arrangedto be actuated through the sterile cover.
 19. A device for controllingimage parameters comprising: a multi-axis input module that is arrangedas a single-hand operable input module, a control unit of a medicalobservation device, the control unit including the multiaxis inputmodule, wherein the control unit controls image acquisition parametersand display parameters, wherein the observation device comprises animage acquisition unit for providing recorded images having a predefinedrecording pixel quantity and an image display unit for displayingdisplay images having a predefined display pixel quantity, wherein theinput module comprises a plurality of actuation axes, wherein anactuation axis is arranged to be used to select a magnification mode andat least two actuation axes are arranged to be used for moving an areathat corresponds to the display pixel quantity, in consideration of anactual magnification mode, in an area that corresponds to the recordingpixel quantity wherein an actuation element is arranged as four-axisactuation element, wherein an actuation of the a first actuation axisdefines a magnification and a size of an area of the display images inthe recorded images that is associated with the magnification, whereinan actuation of a first actuation axis defines a magnification and asize of an area of the display images in the recorded images that isassociated with the magnification, wherein an actuation of a secondactuation axis defines a focus setting, wherein an actuation of a thirdactuation axis effects a movement of the area that is covered by thedisplay images in an area that is covered by the recorded images, in afirst movement direction, and wherein an actuation of a fourth actuationaxis effects a movement of the area that is covered by the displayimages in the area that is covered by the recorded images, in a secondmovement direction Y that is inclined with respect to the first movementdirection.